Desuperheater control



May 29, 1928.

c. HQLSMOOT DES-UPE'RHEATER CONTROL Filed A ril '2, 1927 INVENTOR. Owns:#541007 A TTORNEYS.

, steam transfers its heat to Patented May 29, 192$ UNITED STATES1,671,686 PATENT OFFICE.

cmnnns a. snoop, or mrnnwoon, NEW JERSEY. nnsurnnnmrnn common.

Application filed April 7,

This invention relates to steam desuperheaters used for transferring toa body of water any excess heat that the steam may have over thatdesired for an engine .or other receptive device and it relates moreparticu larly to desuperheaters of the non-contact type in which, likesurface condensers, the the water through a conducting partition.

The amount of supei'heat is generally subject to fluctuations. and inthe absence of proper control may pass steam to the recep-- tive device,having an excess temperature, whereas it may be desired that thetemperature of the steam supplied to the device remain at constanttemperature; The body of water designed to absorb the surplus heat, maybe made to act as a compensator, acting to absorb the surplus heat at agreater rate when such; surplus is excessive, so that the desuperheatedsteam may flow from the desuperheater at a fixed temperature.

The object of the present invention is to supply control means forinsuring such constant temperature without manual aid.

The invention comprises regulating means for varying the area of waterexposed to the superheated steam according to the varia tion in thevolume of superheated steam flow,

the resulting variation in the flow of steam generated in thedesuperheater being made to check the change in heat transferring area awhen said change has reduced the superheat to the required amount.

. of the non-contact Such flow control regulation may be sufliclent whenthe 'temperature of the superheated steam is heldwithin certain limits.

The invention further comprises a thermostat or equivalent device in thelow pressure side which may be used with the aforementioned flowcontrolled checking means, to balance the means causing the change inarea of heat transfer and hold it at such a point as will give aconstant temperature for the low pressure system, and this irrespectiveof variations in the degree of superheat of the high pressure system. 6

The accompanying drawing represents in section a schematic view of anembodiment of my invention.

In the drawing is shown a, desuperheater type, having an outside waterdrum 1, inside of which are placed U- tubes 2 which communicate at oneend with heater are connected the tubes.

1927." Serial 1T0. 181,714.-

a steam'chest 5 which may deliver steam through a reducing valve 6 to alow pressure pipe 7. At 8 is shown a container partially filled withwater,v which container may be the ordinary low pressure boiler or anauxiliary drum; From the lower part'of the container 8 a pipe 9 supplieswater from the container to the desuperheater 1. The up per part of thecontainer 8 and the desuperby steam pipe 10- having a throttle valve 11.The throttlingof this valve 11 provides a means whereby the pressure inthe steam space of the desuperheater may be kept above that of the steamspace in the container 8, the result of which is to hold the water levelin the desuperheat, er below that .of the water level in the container8. The amount of heat transferred from the su erheated steam to thewater in the desuper eater is approximately proportional to the area ofthe pipes 2 that are exposed to the direct contact of the water.

When a greater amount of superheated. steam is flowing, it becomesdesirab e to have a greater amount of water in contact with By means ofpipes 12 and 13 con nected respectively to the steam chests 3 and 5 andto chambers 14 and 15 on op osite sides of a diaphragm 16,-the variation1n the differential pressure between the steam in steam chests 3-and 5is made to communicate motion to diaphragm 16 and from it through rod17, lever 18, rod 19, lever 20, rod 21 and lever 22 to throttle valve11. An increase in flow of steam through tubes 2 will increase thedifferential pressure between chests 3 and 5 and result in a downwardmotion of the,

diaphragm 16 which will cause the throttle diminish and allow the watertherein to rise to a higher level and thus expose more area for thetransmission of heat from .the superheated steam to the water. As acheck to this regulating feature, I place a restriction 23 in thedischarge line from the throttle valve and oneach side of thisrestriction I lead pipes 24 and 25 to having between them a is connectedb same being su stantially the elements of a flow meter. The proportionsof these arts will be made such that the throttle 11 wlll be preventedfrom overtravel and will be checked when the desuperhea-ting operationarrives at the desired point. The discharge diaphragm 28 which line fromthedesuperheater may be connected through pipe 10 to the delivery pipe 7that is receiving the desuperheated steam.

The water level in the desuperheater may also be controlled by athermostat or other thermal device responsive to the temperaturein. thelow pressure pipe. At 30 is shown a thermostat in the low pressure pipeoperating throu h a source of electrical energy 31, a so enoid 32, thecore 33 of which is connected with the lever 18 as shown. It thetemperature of the steam coming from the desuperheater is excessive, thethermostat 30 will close the circuit whereupon the solenoid 32 will liftthe core 33-and cause the further opening of the throttle valve 11. Thewater Will then rise in the desuperheater, taking away more heat fromthe superheated steam until the temperature of the low pressure steam inpipe 7 has been reduced sufiiciently to cause the thermostat 30 to againopen the circuit and, stop the further 0 ening of the throttle 11. It 1sto be observe that the operation of the thermostatic control is, to acertain extent, similar to a micrometer adjustment to the .flow controldevices, but it can also be used beneficially in connection therewith.

I have shown the throttle 11 as located in the steam line 10 connectingthe desuperheater steam space with the space above the water of thereservoir but it may evidently be placed in the water line 9, its solefunction being to control the difierence in level of the water in thetwo containers 1 and 8 and through this control of level to regulate thearea of water exposed in the desuperheater.-

1. In a regulator for controlling the out put of a desuperheater, thecombination comprising a desuperheater having means' for varying thearea of heat transference from steam to water, means responsive to afunction of the quantity of heat transferred to var said area, and meansresponsive to the v0 ume of steam generated in the desuperheater tocheck the said first-mentioned responsive means.

2. In a regulator for controlling the output of a' desuperheater, thecombination comprising a desuperheater having means for varying the areaof heat transference from steam to water, means responsive to the flowof superheated steam through the desuperheater to vary the said area,and

means responsive to the volume of steam generated in the desuperheaterto check the first mentioned flow responsive means.

3. In a regulator for controlling the output of a desuperheater, thecombination comprising a desuperheater having means for varying the areaof heat transference from steam to water, means responsive to the flowof superheated steam through the desuperheater to vary the said area,means responsive to the volume of steam generated in the desuperheaterto check the first mentioned flow responsive means, and means subject tochange of temperature of the desuperheated steam to also check the meansfor varying the area of heat transmission.

4. In a regulator for controlling the output of a desuperheater of thenon-contact type in which the water level is regulatable, a reservoir ofwater adapted to have its water level above the water level of thedesuperheater, a pipe connecting the reservoir and the desuperheaterbelow their water levels, a pipe connecting the reservoir andesuperheater above their water levels, means for restraining the flowof water from the reservoir to the desuperheater, means responsive to afunction of the quantity of heat transferred to vary said restrainingmeans, to allow the water to assume a higher level when more heat is tobe transferred, and means responsive to the volume of steam generated inthe desuperheater to check said change in the restraining means.

5. In a regulator for controlling the outtype in which the water levelis regulatable,

a reservoir of water adapted to have its water level above the waterlevel of the desuperheater, a pipe connecting the reservoir and thedesuperheater below their water levels, apipe connecting the reservoirand desuperheater above their water levels, means for restraining theflow of water from the reservoir to"; the desuperheater, meansresponsive to a function of the quantity of heat transferred tovary saidrestraining means, to allow the water to assume a higher level when moreheat is to be transferred, and thermostatic means responsive to thetemperature of the desuperheated steam to check the effort of the saidfunction responsive means.

CHARLES H. SMOOT.

